具有低高度的UIRefreshControl UICollectionView

Question

I have a view which contains another view on the top part, which I'm using to show some basic information. It has about 40% of the total view height. Below that "header" view, I'm using a UICollectionView which is scrollable. Now I've added a UIRefreshControl to my UICollectionView, but refreshing does never occur, because the user can't pull down the UICollectionView that far. When I reduce the height of the top view, it starts working because there's enough space to pull the collectionview down then.

Here's how I'm adding the refreshControl:

    self.matchDetailRefreshControl = UIRefreshControl()
    self.matchDetailRefreshControl.addTarget(self, action: #selector(MatchDetailViewController.fetchAll), forControlEvents: .ValueChanged)
    self.collectionView!.addSubview(self.matchDetailRefreshControl)
    self.collectionView!.alwaysBounceVertical = true

Have a look at this screenshot for reference:

As you can see, the UIRefreshControl doesn't get fully filled, while my finger is already at the bottom of the screen.

How can I fix that?

Answer 1

You can implement scrollViewDidScroll. If the scrollView's contentOffset is past a certain point, then implement your refresh programmatically using beginRefreshing()

eg (with the refresh control connected to an outlet named 'refreshControl')

func scrollViewDidScroll(scrollView: UIScrollView) {

    let currentOffset = scrollView.contentOffset

    let yOffset = currentOffset.y

    if yOffset < -30.0 && !refreshControl.refreshing {
        refreshControl.beginRefreshing()
    }
}

don't forget to set the scrollView's delegate to self if you haven't already

edit: sorry it's beginRefreshing(), not startRefreshing().